Question

find the perimeter of the figure below. notice that one side length is not given.
assume that all intersecting sides meet at right angles.
be sure to include the correct unit in your answer.

Explanation:

Step1: Find unknown vertical side

The total vertical length on the left is 15 cm. The known vertical segment on the right is 7 cm, so the unknown vertical side is $15 - 7 = 8$ cm.

Step2: Find unknown horizontal side

The total horizontal length on the top is 10 cm. The known horizontal segment at the bottom is 8 cm, so the unknown horizontal side is $10 - 8 = 2$ cm.

Step3: Sum all side lengths

Add up all the sides: $10 + 7 + 8 + 6 + 8 + 15 + 2 + 9$
Wait, correct sum: list all sides clearly: 10 cm, 7 cm, 8 cm, 6 cm, 8 cm, 15 cm, (10-8)=2 cm, (15-7)=8 cm. Now sum:
$$10 + 7 + 8 + 6 + 8 + 15 + 2 + 8$$
Calculate step by step:
$10+7=17$; $17+8=25$; $25+6=31$; $31+8=39$; $39+15=54$; $54+2=56$; $56+8=64$

Answer:

64 cm